Microwave-assisted synthesis of CuO/MnO2 nanocomposites for supercapacitor application

Copper oxide/manganese dioxide (CuO/MnO2) nanocomposites were prepared by a facile microwave-assisted synthesis method in an ordinary household microwave oven and used for electrochemical supercapacitor. The nanocomposites were characterised by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Electrochemical results demonstrate that CuO/MnO2 nanocomposites have better capacitance performance than pure CuO material. The CuO/MnO2 nanocomposites have a high specific capacitance of 499.0 F/g at a current density of 0.5 A/g in 6 M KOH electrolyte. In addition, an asymmetric supercapacitor with activated carbon as a negative electrode and CuO/MnO2 nanocomposite as a positive electrode was also successfully prepared. This asymmetric device exhibits a high energy density of 32.07 Wh/kg at a power density of 375.02 W/kg and fairly good cycling stability.